1. Technical Field
An aspect of the present invention relates to an ophthalmic photographing apparatus for photographing a tomographic image of an examinee's eye.
2. Related Art
There is known an ophthalmic photographing apparatus (Optical Coherence Tomography: OCT) which has an interference optical system and photographs a tomographic image of a fundus. The interference optical system of this apparatus splits light emitted from a light source into measurement light and reference light. This interference optical system then guides the measurement light to a predetermined region of an examinee's eye, while guiding the reference light to a reference optical system. Subsequently, the interference optical system synthesizes the measurement light, reflected on the predetermined region of the examinee's eye, with the reference light, to obtain interference light, and thereafter makes a light receiving device receive this interference light. In such an apparatus, an optical member for changing an optical path length is moved in an optical-axis direction. This can adjust an optical-path difference between the measurement light and the reference light in accordance with a difference in ocular axial length (refer to JP-A-2008-29467).
Incidentally, in such an apparatus as described above, an adaptor having a lens system for moving a focal position of the measurement light from the fundus to an anterior segment can be mounted in an inspection window, thereby to also photograph a tomographic image of the anterior segment.